Ignition system



D. B. HUGHES.

IGNITION SYSTEM. APPLICATION FILED OCT. 22, I910- RENEWED SEPT. I, I920.

Patented se t. 6,1921.

, Jf7zz/e7ft07 y I tag/4 1% UNITED STATES PATENT OFFICE.

DOW B. HUGHES, OI CLEVELAND, OI-IIO, ASSIGNOR, BY MISNE ASSIGNMENTS, T0 MOTOR IGNITION 6'0 DEVICES COMPANY, A CORPORATION OF WEST VIRGINIA.

Specification of Letters Patent.

IGNITION SYSTEM.

Patented Sept. 6, 1921.

Application flled'october 22, 1910, SerialNo. 588,426. Renewed September 1, 1920. Serial No. 407,505.

To all whom it may concern:

Be it known that I, Dow B. HUGHES, a citizen of the United States residing at Cleveland in the county of duyahoga and State of Ohio, have invented a certaln new and useful Improvement in Ignition Systems, of which the following is a full, clear, and exact description.

This invention relates to ignition systems and is designed as an improvement over the systems disclosed in my ending applications for ignition systems, erial No. 553,111, filed April 2nd, 1910, and Serial No. 557,889,

' filed April 27th, 1910. The object of the' present invention is to provide an ignition system which possesses all the advantages of my prior systems but which is simpler, consistsof fewer parts and is less expensive to install than the latter.

The system arranged "and operated in accordance with the present invention is, generically considered, similar to the systems of my prior applications in the respect that the igniting spark is produced by first discharging across the spark electrodes a high frequency current which produces an arc of low heat value and materially reduces the resistanceof the air gap, and by then following up this arc with an arc of high heat value and long duration produced by current passing across the electrodes directly from the main source, of current, the high freuency current being preferably created by t e rapid charging and disruptive discharging of a condenser produced by the operation of a suitably arranged make and break' device and being transmitted to the spark plug b a disruptive discharge coil.

In t e present case I employ fora multispark plug ignition system a single condenser, preferably of small capacity and a single dlsru tive discharge coil and distribute the hig frequency current through a distributer tothe different spark plug connections which are also directly connected to the source of current so that as the high frequency current is discharged across the terminals of each spark plug, it will be immediately followed up by current from the source of current, producing successively at the difierent spark plugs, arcs oflow heat value and arcs of high heat value which insure total ignition of the mixtures in the cylinders.

' My invention may be further briefly summarized as consisting in certain novel combinations and arrangements ofparts which wlll be described in the specification and'set forth in the appended claims. i

In the single figure of the drawings, I have shown iagrammatically a system embodymg my invention.

Referring now to the drawing, 10 represents a source of current which as here shown 1s a magneto having an armature provided w1th a coil 11 which need be wound for very low yoltages only, inasmuch as the voltage requlred to create an arc of highheat value after the arc of low heat value is formed by the high frequency current is very small as compared with the voltages required with 1gn1t1on systems commonly employed, even the systems known as low voltage systems. One terminal of the winding 11 is grounded as shown, and the other terminal is connected by conductor 12 toboth the primary 13 and the secondary 14; of a disruptive disorder that it will have little impedance or choking effect on the high frequency currents. The condenser will be of small capacity in order that it will be fully charged plugs 19. In this particular instance, the

system is arranged for four cylinders or spark plugs. Consequently, this distributer has four segments 18, but the number of spark plugs may be other than that here shown as the system will operate as effectively with any number of spark plugs as with four, without necessitating the use of more than one coil and one condenser. I also employ for the purpose of creating the high frequency currents a makeand break device including, as here shown, a lever 20 having at its end a contact which cooperates with a contact of an adjustable member 21, the lever being connected by a conductor 22 to the source of current between the latter and the coil, and the member 21 of the make and break device being grounded, as shown.-

by the magneto at the opening of the make odically by a cam 23, which together with the distributer will be driven from the magneto shaft or by other means at the usual rates of speed. It will be noted that the make and break device is in parallel with the armature winding and short circuits the same each time it is closed.

The operation of the system is substantially as follows: \Vhen the make and break device is closed,- the armature winding is short circuited, and energy is stored in the winding during the interval that it is shortcircuited. At the opening of the short circuiting device, the condenser is charged by absorbing the energy previously stored in the source and is thence rapidly disruptively discharged, causing the high frequency current to be set up in the primary 13 which as before stated is in series with the condenser. high frequency current is thus induced in the secondary 14 and as it is of high voltage and low amperage, it will cause an arc of low heat value to be established at that spark plug which is connected to the segment engaged by the movable member of the distributer at the instant that the make and break device is opened. As soon as the arc of low heat value is established, it reduces the resistance of the gap of that particular I plug, and as the plug is connected through the secondary 14 directly to the source of current, an arc of high heat value will be immediately established by current passing from the source of current, the resistance of the air gap being reduced to an extent such that the arc of high heat value can be established by current from the source of current at a very low voltage. The first arc, namely that produced by the high frequency current is, as before stated, of low heat value and is in fact of insuilicient heat value to ignite the mixture, but the are which follows the arc of low heat value is of such high heat value and of such duration that total ignition is assured and further there is no danger of the cylinder missing fire.

As the-distributer arm rotates from one segment to another, the make and break device is closed and thenopened so that the high frequency currents are distributed or set up successively at the spark plugs connected to the successive segments engaged by the movable member of the distributer. Consequently, arcs of high heat value will be established successively at the different plugs inthe, manner above stated.

As before stated, the rapid charging and discharging of the condenser is set up by the opening of the make and break device. To make clear the action of the condenser, it may be said that on the opening ofthe make and break device which had previously short circuited the armature winding, the condenser is charged by the source of current to its full capacity, this being assured by providing a condenser of small capacity as compared with those which are ordinarily employed in ignition systems. As soon as the condenser is charged, and while the contacts of the make and break device are slightly sepa rated, the condenser is then rapidly disruptively discharged, the high frequency current produced thereby continuing until or substantially until the make and break device is again closed. The condenser circuit or high frequency circuit may be traced-as follows :-primary 13, condenser 15, ground, make and break device, and conductor 22, back to primary 13. The make and break device which periodically short circuits the armature therefore plays an important part in the establishing of the high frequenc current, inasmuch asit serves as a spar gap device across which the condenser discharges take place. The width of the air gap at the make and break device need not be very large and can be adjusted as circumstances require, and the arcing which occurs between the contacts of the make and break device by the discharging of the condenser is of such low heat value that no material damage or injury is done to the contacts.

Having thus described my invention, what claim is:

1. In an ignition system for a plurality of spark plugs, a source of current, a distributer having stationary contacts connected to the spark plugs, and its movable member connected to the source of current so that current from said source may be distributed to the several plugs, a condenser, and a disruptive discharge coil, the condenser being connected to the source so that it may be charged thereby and having in its discharge circuit, the primary of the coil, and the secondary of the coil being connected to the movable member of the distributer, and means for periodically causin the charging and disruptive discharging o the condenser.

2. In an ignition system for a plurality of spark plugs, a distributer having its statlonary members connected to the several plugs and itsmovable member connected to the source of current, acondenser and a disruptive discharge coil, the condenser having a series connection with the primary of the coil and the secondary of the coil being connected to the movable member of the distributer, and a circuit breaker adapted to periodically short-circuit the source of current.

3. In an ignitionsystem for a plurality of spark plugs, a source of current, a disruptive discharge coil, a condenser, a distributer having a rotary arm and stationary members connected to the diflerent spark plugs, the condenser and primary of the coil being in series and being connected to the source of current, and the secondary of the coil being connected in circuit with said source of current and being connected to the movable member of the distributer, and hence to the difi'erent spark plugs as the distributer arm is rotated, and means cooperatin with the condenser and connected therewlth to cause the same to be periodically charged and discharged.

4. In an ignition system for a plurality of spark plugs,- a source of current, a dis ruptive discharge coil, a distributer having a rotary arm and stationary members connected to the different spark plugs, the secondar of the coil having one terminal connecte to the source of current and the other terminal connected to the distributer arm, the secondary and each of the difi'erent spark plugs being in the main circuit of said source of current as the distributer arm is rotated, the condenser and primary of the coil being in series and being connected also to the rotary source of current, and a periodically operated make and break device connected to the source of current.

5. In an ignition system for a plurality of spark plugs, a source of current, a disrupt1ve discharge coil, a distributer having a arm and stationary members con nected to the different spark plugs, the secondar of the coil having one terminal connecte to the source of current and the other terminal connected to the distributer arm,

i the secondary and each of the different spark plugs being 1n the main circuit of said source current as the distributer arm is rotated, and condenser and primary of the coil being in series and being connected also to the source of current, and a make and break device for periodically short circuiting the source of current.

6. In an ignition system for an internal combustion engine, means for producing a periodically fluctuating current, includlng an element operated in synchronism with the cyclic period of the engine, a disruptive disc arge coil, a condenser, a distributer having relatively movin members for selectively distributing igmtion current to a plu rality of spark plugs, the condenser and primary of said coil being in series and being connected to the source of current, and the secondary of the coil being connected in circuit with said source of current and being connected to the distributer, whereby said secondary is selectively placed in circuit with said spark plugs as functions.

In testimony whereof, I hereunto afiix my signature in the presence of two witnesses.

DOW B. HUGHES.

Witnesses:

H. R. SULLIVAN, A. KwIs.

the distributer 

